PHP回复javascript到html但java脚本不起作用

Question

我试图通过ajax将javascript和html按钮一起回到 .html 页面，但是当我点击按钮控制台时说没有执行任何功能时，有一个功能在HTML身体我不知道什么是错的我的问题似乎是愚蠢但我google了很多我没有找到任何适当的解决方案

我的PHP代码

echo "<button type='button' onclick='alerting();'>Testing Script</button>";
echo '<script type="text/javascript">function alerting(){alert("dfdgfg");}</script>';   

的Javascript

HttPRequest = false;

    if (window.XMLHttpRequest) { // Mozilla, Safari,...
        HttPRequest = new XMLHttpRequest();
        if (HttPRequest.overrideMimeType) {
            HttPRequest.overrideMimeType('text/html');
        }
        } else if (window.ActiveXObject) { // IE
        try {
            HttPRequest = new ActiveXObject("Msxml2.XMLHTTP");
            } catch (e) {
            try {
                HttPRequest = new ActiveXObject("Microsoft.XMLHTTP");
            } catch (e) {}
        }
    } 

    if (!HttPRequest) {
        return false;
    }


    var url = 'http://localhost/text.php';
    var pmeters = "tschoolid=" + encodeURI(localStorage.getItem("txtPassword1")) +
    "&tuserid=" + encodeURI(localStorage.getItem("Userid"));


    HttPRequest.open('POST',url,true);

    HttPRequest.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
    HttPRequest.setRequestHeader("Content-length", pmeters.length);
    HttPRequest.setRequestHeader("Connection", "close");
    HttPRequest.send(pmeters);


    HttPRequest.onreadystatechange = function()
    {

        if(HttPRequest.readyState == 3)  // Loading Request
        {


        }

        if(HttPRequest.readyState == 4) // Return Request
        {
            var retVal = HttPRequest.responseText;

            document.getElementById("Header_section").innerHTML = retVal;       


        }


    }